USB connectors come in different sizes and types. Not all size and type combinations are valid, and only a few of them are used in majority of applications.
USB is asymmetrical: there's a host (originally a computer) and a peripheral device (flash drive, mouse, mobile phone etc.) The original type A/type B dichotomy reflects this asymmetry: type A was intended for hosts and type B for peripherals. Full-size type A is the most common, large rectangular connector with a horizontal plastic tab taking half of the slot. Full-size type B is the square-ish connector with two truncated corners, nowadays used mostly to connect printers.
Then there's the mini size, which was created to be used in devices too thin to fit a full-size connector. Mini type B was used for some time, superseded by even smaller micro type B which is still very common in mobile phones and various devices that charge from USB. Mini type A exists, but is practically unheard of. There's also mini type AB and micro type AB, but I've never seen one of these.
Most recently, the type C connector was introduced. Its original form factor is small enough to replace micro type B. It's also reversible, which is awesome. Type C can be used both for hosts and peripherals.
So the most common USB types are:
"Micro B" on the image you've posted is just an unofficial, shorter way of writing "micro USB type B". "Micro-USB" is the same thing.